A. Field of the Invention
The invention here relates to improving respiratory function of patients suffering from lung disorders through a program of breathing exercises. In particular, the invention relates to a method which provides feedback signals to a patient performing breathing exercises so that during the exercises target pressures for drawing air into the lungs and target rates for breathing are both achieved.
B. Description of the Prior Art
Breathing exercises have previously been prescribed to increase the inspiratory muscular endurance of persons having chronic obstructive pulmonary diseases such as chronic bronchitic emphysema, breathing problems caused by chest wall or muscle disease, or any condition requiring increased inspiratory muscular endurance. These previous exercises have included use of resistive training devices which are held in the mouth of a person doing breathing exercises while passage of air through the nose is blocked by a clip. The resistive training device restricts the flow of air into the lungs by including an orifice with a small cross-sectional area through which air must pass when the person inhales. When the person exhales, a one way valve, closed during inhalation, is open to facilitate unhampered passage of air The restriction of air flow is adjustable in these previous resistive training devices. During a set period of time each day a person exercising with the resistive training device breathes through the device, with the restriction to air flow set at a fixed value. Depending on the improvement of inspiratory muscle endurance, as measured by the onset of stress, e.g., tiring, shortness of breath, increased pulse rate and the like, the restriction to air flow through the training device can be increased so that the person using the training device must increase the use of the inspiratory muscles in order to breathe. A previously known training device which functions as discussed above, is described in U.S. Pat. No. 4,533,137 which issued Aug. 6, 1985 to Leonard J. Sonne.